1. Field of the Invention
The present invention relates to a slide fastener stringer, and more particularly to a water-resistant slide fastener stringer having seal means for protection against water leakage between intermeshing rows of coupling elements.
2. Description of the Prior Art
Known water-resistant, or water-proof, slide fastener stringers comprise a water-resistant stringer tape and coupling elements mounted thereon by extrusion molding. The stringer tape is composed of a woven or knit web having face and back layers of elastomer such as natural or synthetic rubber, and a sealing fin projecting from the element-supporting edge of the stringer tape toward the coupling heads of companion coupling elements. When two such stringers are coupled together and immersed in water, the sealing fins are brought into tight contact with the coupling heads, thereby hermetically sealing the intermeshing coupling elements against water leakage. Since the sealing fins are pressed against the coupling elements during use, it is necessary that the coupling elements be firmly attached to the stringer tapes for protection against unwanted displacement or tilting under usage, which would lower the water-resistant capability and make the slide fastener malfunction. Attempts to attach the coupling elements too securely to the stringer tape, however, would render the slide fastener less flexible than required, resulting in the danger that the interdigitating coupling elements might become separated or broken apart.